Hello all,
I have a '76 Ranchero with a 351M. I'm replacing the distributor and when I took the old one out it must have dislodged the oil pump shaft because a new distributor would not go in the old one's place. It would almost go down all of the way, but it was about a half inch shy of being fully seated. Soooo....
I tried using a deep socket hex bit and a long extension to rotate the pump shaft while pushing down to seat it, to no avail.
Then I tried using a magnet to get the oil pump shaft out of the engine, and unlike when I installed it, it won't come out freely. It gets caught in the bore, like there's something stuck to the end of it that wont fit through the hole. Even when I get it out far enough to grab it it doesn't break free, though I'm reluctant to pull too hard, in case the thing that's stuck to the shaft comes loose and falls into the crank case.
Isn't the oil pump shaft just a solid hex shaft that is the same at both ends? I can't figure out why it doesn't just come out like it should. I think it may have taken a part of the oil pump up with it when I removed the old distributor, and now it wont seat like it should. Any ideas? I've been working on this for 3 days straight now and I can't figure it out. Should have been a pretty straightforward replacement, right? I appreciate any ideas, thanks in advance.

Shawn

 

First off it sounds like the shaft may have been installed upside down. There is a retainer clip on the shaft that is there to keep the shaft from being removed with the distributor. If the hex shaft does come out of the top of the oil pump it is difficult to get it back in without dropping the shaft in the pan. Normally the shaft can only be moved up and down a fraction of an inch.

Sometimes if the pump shaft or the engine turns slightly it is difficult to get the distributor to drop back in. Place the engine at TDC compression stroke and try the distributor. If it does not drop in some people pull the distributor and turn the hex shaft slightly, other people move the crank position slightly. Keep working until it drops in. HOPEFULLY it will be in the right position when it goes or otherwise you will have to go thru the whole process again. You may be able to move that hex shaft just the right amount tho to get it right the next time.

Put anti-seize in the distributor pump drive hex. Also put anti-seize on the aluminum surface of the distributor where it goes into the block.

 

I had to rotate my pump shaft ever so slightly until it lined up right to drop the dizzy down. I just kept fiddling with it until it aligned.

 

Thanks for the ideas, I'll give them a shot tomorrow. I didn't know there was a retainer clip on the shaft, I didn't see it when we assembled the engine. The thing that concerns me is that I cannot remove the shaft from the engine while the distributor is out. It comes almost all the way out, but then stops short. It seems like there is something stuck to the other end. I went to Autozone to check out a new oil pump, just to see what the other end looks like (It's been a long time since I installed it) and there is a hardened metal hex sleeve (looks like the one on the bottom of the distributor) that is seated in the cast metal assembly, which presumably turns the pump mechanism. I wouldn't think that that part would break, but it sure feels like there is something stuck to the other end of that shaft and if there is I think that may be the culprit. I may drain my oil tomorrow to see if there are any shavings in the pan, the oil pump may have disintegrated, but then again I haven't had any problems with oil pressure, the pump seemed to be doing its job up until now. Thanks again, and if anyone else has any ideas, please keep them coming. Cheers,

Shawn

Oh, and Beeboy- I know what you mean, we had to fiddle with it to get it in originally, but we must have tried it for 3 hours solid last night. It just doesn't want to go. Thanks!

 

you can just "bump" the solenoid and the dizzy will drop in onto the shaft. use the solenoid to rotate the engine around until the timing marks line up again and the rotor should be pointing to the #1 tower position (about 12:30-1:00). if not, lift it up and correct the proper amount, bump to seat , recheck. this only takes 1 minute or so. if you are starting out not knowing where the engine is, pull the pass front plug and check for compression, then line up the timing marks. the shaft will turn a small amount as it engages the cam gear, so allow for this.

 

when you turn the shaft, can you feel the resistance of the pump? Could the shaft not be dropped all the way into the pump?

 

When I turn the shaft there is no resistance at all. I remember when I primed the new pump when installing this engine. I nearly blew the motor on my power drill, so I was surprised that there was no resistance when I put a deep-well socket on the shaft and turned it by hand. I'm pretty sure that something broke free of the oil pump and remained attached to the drive shaft when I removed the distributor, and now it won't fit together like it should. I will try bumping the engine a bit tomorrow and see if that makes a difference, I'm going to see if I can seat the distributor regardless of whether or not it's in the right position. I just want to know if it will ever fit. If I can get it to seat properly after moving the crank position at least I know that it will seat eventually, then I'll worry about getting TDC. Right now I want to try everything I can that doesn't involve lifting the engine and removing the oil pan.

Thanks again you guys, this helps bigtime.
Shawn

 

at this point do not start the engine until you are POSITIVE that you have the oil pump driveshaft in the oil pump and you can build oil pressure by turning the shaft! if you don't feel any resistance, then you don't have the shaft in the pump and you will not pump oil!

 

I can't start it until I get the distributor seated fully. Do you think that if it seats all the way that I can be certain that everything is lined up okay? I definitely don't want to blow this engine, it's only got a couple thousand miles on it.

Shawn

 

Oh, and while I have this post going, I'm trying to locate the ballast resistor or resistor wire, and haven't been able to find it. I'm assuming that there is a resistor wire somewhere in one of the harnesses, do any of you guys know where? I don't know if you need to know this, but my duraspark module is the one with the blue grommet. That seems to be what differs on the 351m setups. Thanks,

Shawn

 

You crank the engine and the distributor drops in.

The shaft won't pull out because it has a large press fitted washer installed on the bottom end to prevent it from being pulled out.

 

You can put a socket on it in a drill, turn the ignitio to on, and watch the guage while someone else turns the drill. That will answer your question. Mine comes out with that washer on it. You should be able to feel around and get it back on. I experimented a little bit when i put my engine together. I had a very hard time getting it to drop into the pan. It just sat in the top of the oil pump if it was in wrong.

 

the press on washer is supposed to be at the top of the shaft just under the block metal where the dizzy drive gear goes. there is no way the shaft will come out if it is installed correctly. the shaft should have minimal play up and down, just so that the washer doesn't rub and create metal chips as it turns. when i install an oil pump i move the washer up to the top of the shaft a bit and let the oil pump push the shaft up towards the dizzy hole. this locates the washer very close to the block and locks the shaft in, preventing it from being pulled out of the pump with the dizzy when you lift it.

 

Not to be a jerk, but did you compare the old distributor with the new distributor, particularly the gear, before you tried putting it in?

You sometimes have to rotate the oil pump shaft slightly to get it to drop, because the relationship between the teeth on the gear to the hex at the bottom of the shaft changes with a new distributor. Had that problem, couldn't get it to go, gave up on keeping the timing, and jumped the battery to starter relay a coupla times and in it went.

Of course, I had to fiddle with jumping the engine some more to get the rotor lined up kind of right for the initial timing.

ash
['It's finicky, not horrible.']

 

Gee, if you had read my first post you would be done by now...